The invention relates to the field of communications. In particular, one embodiment of the invention relates to a system and method for extracting symbol timing from preamble symbols of a signal in a reliable, robust and computationally efficient manner.
Many modern communication schemes rely on digital information transmissions. Information is digitized and then transmitted via an analog or digital carrier signal.
As illustrated in FIG. 1, a transmitter device 102 typically modulates digitized information into a carrier signal. The transmitter device then transmits the carrier signal on a channel to a receiver device 104 over a transmission medium 106. The receiver device 104 typically demodulates the received carrier signal to extract the digital information found therein.
In typical communication schemes, a receiver device 104 determines where the received digital information begins. Before demodulating a received signal, the receiver device 104 aligns or synchronizes the received signal in order to determine the start of a signal, information, or message and/or to determine whether such signal contains a message. Synchronization permits the device to extract accurate information from the signal.
The synchronization process is sometimes made more difficult when the carrier signal and/or information therein has been corrupted, altered, and/or is more difficult to detect as a result of noise, interference, or some other factor. The transmission medium 106 over which the carrier signal is transmitted is one place where the carrier signal and/or information therein are susceptible to such degradation 108. The transmission medium typically includes wired and/or wireless (air) transmission paths.
Despite the possible degradation of a carrier signal and/or information therein, a receiver device must be able to detect a signal and determine its content in order for communications to occur.